1. Field of the Invention
The present invention relates to system and method for displaying degradation of a power storage device and, more specifically, to degradation displaying system and method for displaying information related to evaluated state of degradation of a power storage device for running mounted on a vehicle.
2. Description of the Background Art
Japanese Patent Laying-Open No. 5-227669 discloses a battery charger for an electric vehicle. The battery charger is provided with a battery management system in which a database of information related to a battery mounted on an electric vehicle is formed and all pieces of information are recorded and diagnosed on the charger side to enable appropriate charging and the like in accordance with the state of use of the battery.
Specifically, a battery, an IC card reader/writer, a vehicle sensor for detecting driving information related to the vehicle, a battery sensor for detecting information of the battery at the time of use and the like are mounted on the vehicle. Signals from the vehicle sensor and the battery sensor are input to the IC card reader/writer, and recorded on an IC card. The information recorded on the IC card is read as needed by the IC card reader/writer and displayed on a display unit on the vehicle. Thus, it is possible for a driver to know battery charge amount, life and so on.
At a charge service station, a charging facility, a charger control unit, an IC card reader/writer and the like are provided. The IC card reader/writer includes analyzing means for reading battery-related information recorded on an IC card and for obtaining resulting diagnosis related to charging, and the resulting diagnosis is applied to the charger control unit. The charger control unit controls start and end of charging by the charger, charging voltage and current and so on, in accordance with the diagnosis applied from the IC card reader/writer.
The battery charger enables efficient charging in accordance with the types of batteries based on the battery diagnosis and prevents loss of electric energy.
The battery charger described above displays state of degradation such as battery life to a user (driver) of the vehicle, while there is a need among dealers in charge of vehicle maintenance and vehicle manufacturers to know the state of degradation of power storage devices for running (batteries and capacitors). Knowing the state of degradation of the power storage device, it becomes possible for the dealers to do appropriate maintenance, and it becomes possible for the manufacturers to examine the state of degradation of the power storage device with the result of examination fed-back for future improvement.
Users, dealers and manufacturers, however, want different pieces of information, and it is necessary to display state of degradation appropriate for intended use of each of the users, dealers and manufacturers. The battery charger disclosed in the laid-open application described above does not include any consideration from such a viewpoint.